Method and apparatus for detection of analyte using an acoustic device

Abstract

Methods for detecting analytes in a sample are provided. A plurality of particles, each of which is coated with a capture agent having an affinity for the analyte, is combined with the sample to form a plurality of analyte-particle complexes. The system also includes a transport arrangement for transporting the sample to the sensor surface, and a magnetic field inducing structure constructed and arranged to establish a magnetic field at and adjacent to the sensor surface. The resonant sensor produces a signal corresponding to an amount of analyte-particle complexes that are bound to the sensor surface.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of U.S. Ser. No. 11 / 183,484 filed on Jul. 18, 2005, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60 / 690,592, filed Jun. 15, 2005. This application also claims the benefit of U.S. Provisional Patent Application Ser. No. 60 / 676,759, filed on May 2, 2005, entitled “Methods and Apparatus for Viral Load Detection and Measurement.”TECHNICAL FIELD[0002]The present invention relates to methods for detecting one or more analytes in fluid samples.BACKGROUND OF THE INVENTION[0003]Significant challenges for a system that detects analytes (e.g., chemical and biological agents) in liquid media include concentration of the analyte in the media, and transport of the analyte to a sensor surface. For biological applications, concentration issues generally arise since the concentrations of such analytes tend to be low. Additionally, biological analytes (e.g., cells, cell fragments and ma...

AI Technical Summary

Benefits of technology

The present invention provides methods for detecting the presence of analytes in a sample using magnetic particles coated with a capture agent. The method involves introducing the particles into a fluid chamber and monitoring the signal output from an acoustic device that has a specific analyte bound to it. The method can be used to detect estradiol, immunosuppressants, and other molecules in a sample. The technical effects of the invention include improved sensitivity and accuracy in detecting analytes and the ability to adjust drug dosage based on the level of analyte present.

Problems solved by technology

Significant challenges for a system that detects analytes (e.g., chemical and biological agents) in liquid media include concentration of the analyte in the media, and transport of the analyte to a sensor surface.

For biological applications, concentration issues generally arise since the concentrations of such analytes tend to be low.

Additionally, biological analytes (e.g., cells, cell fragments and macromolecules such as proteins and nucleic acids) tend to be relatively large; hence, transport issues arise because these larger analytes diffuse in fluid solution very slowly.

An elevated level of estradiol is correlated with increased risk of developing breast cancer.

However, a low estradiol level is correlated with an increased risk for vertebral fractures.

However, tamoxifen can lower serum estradiol levels to a point that increases the incidence of vertebral fracture.

The detection of small molecules such as estradiol is often difficult not only because of potentially low levels in the sample, but also because of the limited number of suitable capture agents that can be used to bind the small molecule analyte.

As a result of such limitations, it is often difficult to design or modify existing assays, such as enzyme-linked immunosorbant assays that are sensitive and specific enough to detect low levels of the small molecule analyte.

The delay associated with analyzing a sample makes it difficult for a doctor to accurately specify a proper treatment.

Acoustic excitation has been used to draw cells to field nodes, but it is difficult to use this technique alone to transport material to a surface.

Electrical fields (electrophoresis and dielectrophoresis) have been used to enhance transport but are not universally applicable to all analytes and sample types.

Furthermore, the electrical properties of microbes can vary within a given species and strain, making it hard to predict system performance under all intended operating conditions.

This requirement can conflict with the optimum binding or wash conditions in an assay.

Also, electrical fields can dissipate energy and heat conductive fluids (e.g., 0.1 M phosphate buffer solution), which is undesirable since heating can damage the biological analytes.

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